Aromatic borane thallophyticides



United States Patent Other:

3,062,708 Patented Nov. 6, 1962 3,062,708 AROMA'EIQ BORANETHALLQPHYTICIDES David M. Updegraif, North Saks, Minn, assignor toMinnesota Mining and Manufacturing Company, St. Paul, Minn a corporationof Delaware No Drawing. Filed .ian. 4, 1960, Ser. No. 71 30 Claims. (Cl.167-39) This invention relates to a process for inhibiting the growth ofmicroorganisms and more particularly for preventing or terminating thegrowth of organisms of the division Thallophyta, and to compositionsefiiective for this purpose.

Processes for killing or inhibiting the growth of microorganisms such asthe lower non-vascular plants are of great utility in virtually allphases of argriculture, industry and household activities since theeifects of such microorganisms include such diverse results as diseasesof plants, deterioration of materials and spoilage of goods.Furthermore, since these lower forms of life are readily distributedfrom place to place, as for example, by air dispersal, being in the formof individual cells which may be thought of as spores, contamination ofa given material by numerous species is a common result. This means thatto achieve protection of material such as paper, plastic or clothagainst one species or even one family of such organisms may disturb apossible natural balance of species, an antagonism such as has beenamply shown, for example, between the mold Penicillium and manybacteria. Disturbance of this balance, while protecting against onespecies, may leave the way open for rapid multiplication and attack byanother species. It is accordingly apparent that what is needed for manyapplications is a broad spectrum of activity against a number of typesof microorganisms.

it is an object of this invention to provide broadspectrum bactericides.A further object is to provide a process for the inhibition and/ortermination of growth of certainmicroorganisms. A still further objectis to provide compositions for accomplishing these objectives. Otherobjects will become evident from the disclosure hereinafter.

While the classification of plants has proceeded over at least twocenturies, it must be recognized that there is still a dispute withrespect to the classification of some microorganisms and accordingly itwill be noted that the terms herein used are to be understood in lightof the present disclosure, as these generally will be correctlyunderstood even though they may be somewhat more embracing in scope thanwhen employed by some taxonomists.

In accordance with the above and other objects of this invention it hasbeen found that the life cycles of numerous microorangisms are impairedand terminated by application thereto of low concentrations of the classof compounds best described as triarylboranes. Broadly speaking, thesecompounds have been known to the art for many years, yet theirsurprisingly high activity against microorganisms apparently has beenunknown heretofore.

As will become evident from reading the present speci-' fication, thespectrum of activity of these compounds is very broad, and organismssusceptible to them include members of several well-recognized divisionsof the plant kingdom as well as some organisms which are sometimes butnot universally considered to be very low members or" the animalkingdom. Because the majority of these organisms are recognized asbelonging in the well-recognized division Thallophyta, and the othersmight be so classified, this term is here employed to include allmicroorganisms subject to the process of this invention, whichaccordingly may be termed thallophytes. Thaliophytes are usually haploidorganisms reproducing asexually or vegetatively, although it will beunderstood that many of these organisms are also capable of sexualreproduction. V

In order to clarify this definition still further, the major classes andorders of organisms falling under this division are tabulated:

Schizornycetes, e.g.:

Bacillus subtilis Xanthomonas phaseoli M icroc ccus pyogenes var. aureusMycobacterium phlei Pseudomonas aeruginosa Serratia marcescensEscherichia coli (Gratia strain) Escherichia coli (Crookes strain) Microeoccus lyso'deikticus Areobaczer qeroge'nes Neisseria c'atarrhalisProteus moiganii Alkaligenes viscosus M icrvcoccus pyogenes var. aureus(penicillin-resistant strain) I Desulfovibrio 'aestuarii Myxomycetes,e.g.:

Plasmodiophora brassicae Phycomycetes, e.g.:

' Rhizopus nigricans Phytophthora infestans Aph'an'omyces eulichth'esErysiphe p olygoni Pyzhium ultimum Ascomycetes, e'.g.:

Moniiia fructicola Aspei'gillus niger Glomerella cingulata Graphium ulmiTorula Saccharomyces Candida albicans Aspergillus sp. Basidiomycetes,e.g.:

Uromyces phaseoli Fungi Imperfecti, e.g.:

Alterna ria oler'acea Allermzria solam" Sternph'ylium sp. Trichophyron'mentagrophytes Microsporum gypseum M icrosp orum audouini Fusariumoxysporimi Epidermophyton floccOszmz Helminthosporium satz'vtmzRhizoctonia solani Pullulafia' puliu'lans Algae, e.g.:

Euglena gracilis Clzldmyldomonas eugametos It may be noted that theFungi Imperfecti are of,- ganisms sexual reproduction of which has notbeen observed and which may well prove to be Ascomycetes.

It is found that the process of this invention is especially valuable asapplied to certain fungi which are known to be phytopathogenic forhigher vascular plants of agricultural and economic importance such aspeas, beans, tomatoes, cotton, trees including fruit trees, grains andthe like. Products in which the triaryl boranes are incorporated in orover plastics, fibrous materials such as cloth and paper and leather toprotectthem against attack by microorganisms are also particularlyvaluable embodiments of the process of this invention. The prevention ofthe growth of thallophytes in water used in and in the flooding of oilfields for the secondary recovery of oil, is also an important utility.

The triaryl boranes, which may be employed as such, or used in the formof useful complexes for the process of the invention are exemplified bycompounds such as triphenyl borane, tri-p-xylylborane, tri-p-tolylborane, triphenetyl borane, tri-(p-fiuorophenyl)borane,tri-(pmethoxyphenyl)borane, tri-a-naphthyl borane and the like.Triphenyl borane is preferred in the formation of these complexesbecause it is readily prepared from the easily accessible startingcompounds chlorobenzene or brornobenzene and is highly efiective in theprocess of the invention. A convenient method for the preparation oftriphenyl borane is the reaction of a metallic derivative ofbrornobenzene such as phenyl magnesium bromide with boron trifiuoride,as described in Berichte, vol. 55B, p. 1261 (1922).

The triaryl boranes are as a class more or less unstable in the presenceof oxygen, i.e. they apparently combine with the oxygen to form thecorresponding diaryl or monoaryl borinic or boronic acid which hasnegligible thallophyticidal activity compared to the triaryl boraneitself. Further, triphenyl borane and substituted triphenyl boranes,such as tri(p-fiuorophenyl)borane, tri(p-methoxy phenyl)borane andtri(p-tolyl)borane, which exhibit relatively higher thallophyticidalactivity than do the other triaryl boranes, are also relatively unstablewith respect to atmospheric oxygen. This group of compounds may bedesignated generically as the triphenylboranes.

The instability of triphenylboranes is advantageous in certainapplications, e.g. in the killing of the thallophytes on the surface oflaboratory glassware or other articles where it is desired that thesurface will soon thereafter be free of the highly thallophyticidalcompound. In many other applications, however, such as the treatment ofuseful higher plants in order to rid them of thallophyticidal pests, itmay be necessary that the triphenyl borane entity be retained for alonger period of time. It has now been found that it is possible whendesired to stabilize the highly active but unstable triphenyl boraneswhile maintaining their high degree of thallophyticidal activity. Thisis accomplished by forming complexes between the triphenyl boranes andthe class of compounds which can be described as Lewis bases having pKvalues not greater than about 10. The complexes thus formed areordinarily almost indefinitely stable and have the additional advantageof providing a large number of molecules carrying a triphenyl boraneentity having among them a wide spectrum of solubilities in varioussolvents and combinations of. solvents. It will be recognized readily bythose skilled in the art that this degree of control over solubilitycharacteristics vastly increases the utility of these compounds asthallophyticides, since solubility is a major consideration ineffectiveness against particular organisms as well as in methods of useand concentrations of the compositions used.

The triaryl boranes other than the triphenylboranes are generallycomparatively more stable to atmospheric oxygen, and in fact thetrinaphthyl boranes are sufiiciently stable so that additionalstabilization through the formation of complexes is not speciallyadvantageous with respect to many agricultural and industrialthallophyticidal uses. The greatly broader utility of the complexes ascompared to the uncomplexed materials brought about by making itpossible to place the various triaryl borane entities in complexes ofvarying solubility characteristics holds however for the entire class oftriaryl boranes, including the trinaphthyl boranes. For these reasons,the complexes of the triaryl boranes with Lewis bases having pK valuesless than about 10 form a preferred class of thallophyticides of theinvention. Further, for reasons also already given, the complexes of thetriphenylboranes with Lewis bases having pK; values not greater thanabout 10 are a particularly preferred group. (The term PK, is usedherein in its conventional meaning, i.e. the negative logarithm of theionization constant K Lewis bases having pK values greater than about 10do not appear to form complexes with the triaryl boranes which affecttheir stability or thallophyticidal activity. Although the reasons forthis are not known, it may be that if complexes are formed, they areunstable under the conditions encountered in testing or use.

Suitable Lewis base complexing agents are, for example, ammonia,methylamine, dodecylamine, n-tetradecyl amine, ethylenediamine,hexamethylene diamine, tetrahydrofurfuryl aminoethanol, acetylacetoneimide,

benzylamine, triethylenetetramine, N-alkyl propylene, diamines such as12-(N-dodecyl propylamine, dimethylamine, di-n-propylamine,N-methylethanol amine, piperidine, piperazine, morpholine,trimethylamine, trim-propylamine, 3-dimethylamino-propylamine,tributylphosphine, phenyldiethylphosphine, phenyl-dipropylphosphine,pyridine, 3- bromopyridine, y-ethylpyridine, 3-(4-pyridyl)-propanol- 1,3,5-dichloro-pyridine, bis(4-pyridyl) glycol, nicotine, isonicotinicacid, n-butyl nicotinate, nicotinamide, isonicotinic thionamide,[3-picoline, 'y-picoline, imidazole, metallic bases including alkali andalkaline earth metal hydroxides, such as sodium hydroxide, calciumhydroxide, potassium hydroxide, and the like.

Another form of a complex which is useful in the invention is that whichcan be formed by the triaryl boranes with solvents, such as benzene,ethylbenzene, etc. In this case the composition is possibly a solvate orthe like, and the activity displayed as a thallophyticide is that of thetriaryl borane. Complexes of this type with other organic solvents suchas ether, are somewhat more stable than those made with benzene, butthey are likewise not stable in aqueous solutions under the conditionsdescribed herein.

Broadly speaking, the process for the preparation of these complexescomprises preparing an ether solution of the triaryl borane andintroducing the desired Lewis base. The complexes appear to form inmol-for-mol proportions, and ordinarily, there is immediateprecipitation of the ether-insoluble complex. The operation is carriedout in the absence of air. Specific directions for the preparation ofthe complexes of triphenyl borane are set forth in Berichte, vol. 57B,p. 813; ff., 1924, while other triaryl boranes and their complexes aredescribed in the same Journal, vol. 61B, p. 271, 1928; vol. 63B, p. 934,ff., 1930; and vol. 64B, p. 2112, 1931; and in Annalen, vol. 573, p.195, 1951.

The following descriptions, including uncorrected melting points whereavailable, of a number of these complexes will serve to characterizethem and are generally illustrative of the complexes of the invention.

M1. or appearance Triphenylborane-ammonia 179-183 C.Triphenylborane-methyl amine l213 C. Triphenylborane-dodecyl amine Tangrease. Triphenylborane-n-tetradecyl amine Tan oil.Triphenylboranetriethylenetetramine 75-84 C. Triphenylborane-duomeen SRed, viscous oil. Triphenylborane-duomeen 12 Red, viscous oil.Triphenylborane-duomeen C Red, viscous oil.Triphenylborane-dimethylamine 157-l66 C. Triphenylborane-piperidineIvory wax. Triphenylboranepiperazine -175 C.Triphenylborane-trimethylamine 132-138 C. Triphenylborane-pyridine182202 C. Triphenylborane-3,S-dichloropyridine 112115 C.Triphenylborane-bis-(4- pyridyl)glycol 173-181 C.Triphenylborane-y-picoline 135-145 C. Triphenylborane-imidazole 185-190C.

I M.P. or appearance T riphenylborane-sodium hydroxide White solid, doesnot melt below 300 C. Tri( a-naphthyl) boraneammonia l53-157 C. Tri a-naphthyl) boranediethylamine 170-175" C. T ri (u-naphthyl) borane- IItrimethylamine 156158 C. Tri( p-fluorophenyl)boraneammonia l7918l C. Trip-fiuorophenyl) boranetriethylamine 110-115 C.Tri(p-methoxyphenyl)boraneammonia 138-142 C. Tri(p-tolyl)borane-ammonia143-156 C.

As the effective portion of the complex for the purposes of theinvention is the triaryl borane moiety of the compounds, the gist of theprocess is to bring the tr'iarylborane into contact with the organismsto be inhibited in an effective amount. This can be accomplished by aVariety of means. Since the compounds are very strongly active, they areeffective in very small amounts, and therefore are applied in dilutedform. This particularly is necessary when the compositions are to beapplied to plants or useful higher organisms, since the use ofconcentrated dispersions or undiluted triarylboranes causes toxiceffects. Thus, phytotoxicity evidenced e.g. by browning of foliage,dwarfing, reduction in germination of seeds and the like, may beencountered. These untoward effects can be eliminated or reduced byemploying the compositions of the invention for these purposeThallophyticidal compositions of the invention consist essentially of aneffective amount of triaryl borane complex at a concentration of atleast about 0.1 part per million, ranging upward to about 1 percent, ina compatible inert diluent. As extending or diluting means any inertdiluent can be used, which does not adversely affect the substrate towhich the triaryl borane is to be applied, i.e. is substantiallynon-toxic. Water, aqueous solvents, inert powders such as finely dividedchalk, diatomaceous earth and the like, oil-water emulsions and thelike, etc, can be thus employed. Thus, for example, the triaryl- 'boranecomplexes can often be prepared in finely divided form and thoroughlymixed with an, inert dust or fine powder such as diatornaceous earth inconcentration of 100 parts per million of the selected complex. The re'sulting powder may be dusted upon the leaves of plants to be treated,using a dusting gun of conventional type. Adjuvants such as wettingagents, "buffers, thickening agents and the like can also beincorporated into the extending-media, in the same way as is known forother products of the type herein disclosed. The dilute mixtures arereadily applied by any convenient means, as, for example, dusting,spraying, drenching and so on, according to the extending medium usedand the objects to be treated. Furthermore, as an agronomical practice,the triarylboran'e-containing compound can be incorporatedinto the soilin concentration ranging upwards from about p.p.m. Application in amountof about 10 to 100 lbs./ acre is a preferred range for use for thispurpose.

Where growing plants are to be treated, low concentrations of thetriaryl boranes are preferably employed, such as concentrations of theorder of one to 100 parts of the complex per million parts of extendingmedium. Higher concentrations of the triaryl boranes, e.g. in certaincases of the order of 500 parts of the complex per million parts ofextending medium, begin to exhibit herbicidal characteristics towardhigher growing plants. Thus, although this maximum will vary, it appearsthat the effective application to growing plants of the triarylboranecomplexes for the purpose of inhibiting the growth of thallophytesshould be held within a definite range of concentrations below about1000 p.p.m., depending upon the particular situation and the particularplants involved. Ordinarily the ratio of concentrations at which seriousherbicidal activity is noted to the concentrations at which usefulthallophyticidal activity is realized is of the order of 5:1 or greater.

For application to such things as plastics, fibrous materials, leather,textiles, wood, paper and the like, more concentrated preparationscontaining on the order of 0.01 percent by weight to 1 percent by Weightor more of the triarylborane can be used. Since certain of thetriarylborane complexes are of very low solubility in water, solventssuch as pyridine, morpholine, dioxane and tetrahydrofuran must be usedif solutions of high percentage composition are desired. These may bediluted with water for use. Obviously, suspensions, or dilutions usingsolid extending media, are not subject to solubility limitations. Whereorganic solvents are not injurious or toxic for the particularapplication, organic solvent solutions or suspensions of the compoundsuseful in the process of the invention can be employed. I

This application is a continuation-in-part of my prior co-pendingapplication Serial Number 783,167, filed December 29, 1958, nowabandoned. I

The following examples illustrate methods and compositions used inpracticing this invention, but are not to be construed as limiting thescope thereof in respect of the compositions or complexes to be employedor the organisms to be subjected to the process of this invention.Likewise, the particular methods described for application of thecompositions to the substrates which are to be treated to inhibit thegrowth of thallo-phytes thereon are merely exemplary, and it will beapparent to those skilled in the art that other methods can be employed.Such methods are well known to the art and require no furtheramplification herein. The abbreviation p.p.m. in the examples indicatesconcentration in parts per million (on a weight/volume, ezg. milligramsper liter basis). I

The following details pertain to Examples 1-10.

A. The code used to designate the organisms is as follows:

Alg. l. Euglena gracilis Alg. 2 .Chlamya'0m0nas eugametos (male) Fun.3.A spe rgillus niger I Bac. 4.-Microc0cc'us pyogenes var. aureus(penicillinresistant strain) Fun. 5.Candida albicans Fun. 6. Aspergillussp.

All bacteria except Bac. 19 are grown on APT agar slants at 37 c. for 24to 48 hours. From 2 to 4 loop fuls' of growthare carefully removed fromthe surface of the agar and dispersed in 3 ml. of sterile Davismineralsalts basal medium (I. Bach, vol. 66, pp. 129-136, 1953). Onelo-opful of the bacterial dispersion is used to inoculate the testplate. APT agar (Case Laboratories, Chicago), contains the followingingredients: I

All fungi are grown on Myeophil agar (Baltimore Biological Laboratories)at 20-25 C. for 3 to 6 days. Mycophil agar contains:

Grams Agar 16 Phytone Dextrose 10 Water, q.s. to make 1 liter.

A 3 ml. portion of sterile Davis mineral-salts basal medium is thenpoured into the culture tube, and the tube is agitated to obtain a heavyspore suspension. One loopful of the spore suspension is used toinoculate an agar plate used for determination of inhibitory activity.

In carrying out the determination of inhibitory power, the selectedtriarylborane or complex is added to a 10 ml. portion of the sterileliquefied agar medium (described in detail below) at concentrations ofl, 10, and 100 mg./l. Each portion is poured into a sterile Petri dish 9cm. in diameter, and allowed to solidify. The various previouslyprepared inocula of bacteria and fungi are streaked radially on thesurface of the plate (in a radial manner, so that none of the inoculatedportions of agar touch at any point). The plates are incubated at 30 C.for at least 3 days, and examined for evidence of growth. Controlplates, containing no added chemical, are always run concurrently, andalways show good growth of the organisms.

The agar plates are prepared from a synthetic medium made by addingcertain amounts of agar and nutrients to Davis mineral-salts basalmedium.

For the fungi, and those bacteria which will grow on a glucose-mineralsalts agar, there are added 2.0 g. of glucose and 20 g. of purified agarper liter of culture medium.

For those bacteria which require vitamins or amino acids, the agar andglucose-containing Davis medium is used with the following supplements.

Concentration in Vitamin supplement: medium (mg/l.)

Niacin 2.0 Calcium pantothenate 2.0 Pyridoxine hydrochloride 4.0Thiamine hydrochloride 2.0

Biotin 0.0175 Amino acid supplement:

Glutamic acid 600 Cystine 200 Asparagine 800 Alanine 400 'Disodiumethylene diamine tetraacetic acid..- 20

C. The pK values reported are those of the compound which is complexedwith the triarylborane.

D. The Thallophyticidal Index is included as a general approximation ofthe overall effectiveness of the compound in question againstthallophytes.

The index is calculated from the data reported in these examplesrelative to the organisms Alg. I, Alg. 2, Fun. 3 and Bac. 4. If anorganism is inhibited by a one part per million (or more dilute)solution of the compound being tested, a value of is assigned to it forthe index. Similarly, if inhibition occurs at a concentration greaterthan one, but not greater than 10 parts per million, a value of 10 isassigned, and if inhibition occurs at a concentration greater than ten,but not greater than one hundred parts per million, a value of 1 isassigned. If inhibition occurs at a concentration of greater than 100parts per million, a value of zero is assigned. The ThallophyticidalIndex for any compound is the sum of the four values assigned relativeto the indicated organisms.

The exact level of effectiveness of a particular compound with respectto any organism cannot be extrapolated with assurance to others althoughit is clear that the triarylborane-containing compounds are generallyeffective against the thallophytes as a class at relatively lowconcentrations. Thus, no single number designation can provide more thana measure of the probable effective level of a compound against thethallophytes. Experience indicates, however, that the ThallophyticidalIndex furnished a surprisingly dependable (although quite conservative)number value for the utility of a test compound in this field. Thus, forexample, any compound which scores 20 in this index is consistentlyfound to be a valuable thallophyticide, while compounds having indexesof 200 (which are quite rare) are generally at least equal to the mostpowerful commercial thallophyticides. On the other hand, many valuablethallophyticides, including compositions sold commercially for thispurpose, will have Thallophyticidal Indexes of zero. This isparticularly true of those which are commonly applied in concentrationsin excess of 100 ppm, and those which are used in applications in whichthe characteristic of remaining in place for long periods of time(commonly associated with a high degree of insolubility) is required.

Example 1 The inhibiting concentration of aqueous solutions of thecomplex of triphenylborane and ammonia against various representativeorganisms was determined with the following results:

NOTE.Ammonia has the pKi, value 4.74, X 100.

Example 2 Complexes of triphenylborane with several primary ali- Theinhibitory dose of complex of triphenylborane with sodium hydroxideagainst various organisms was determined with the following results:

Inhibitory dose to indicated organism (p.p.m.) Complex oftriphenyiborane with the following- Alg. Alg. Fun. Bac. 'Thallo- 1 2 3 4phyticidal index Sodium hydroxide... 1 1 100 1 301 Inhibitory dose toindicated organism Complex of tripbenylborane with the following- Fun.Fun. Boo. Bac. Bac. Bee.

Sodium hydroxide 100 100 1 100 10 10 Norm-Sodium hydroxide has the pKbvalue 1.

Example 7 Determination of the inhibiting concentration of complexes oftriphenylborane with representative basic nitrogen-containing aromaticheterocyclic compounds against various organisms gives the followingresults:

Inhibitory dose to indicated organism (p.p.m.) Complex triphenylboranewith the following- ThallopKb Alg. Aig. Fun. Bac. phytlcida-l 1 2 3 4index Pyridine 8. 64 1 1 10 10 220 B-br'omopyndine- 7. 82 1 1 100 10 211-Ethylpy Ca. 8. 6 1 1 100 10 211 3-(4-pyridyl)propanol-1 8. 6 1 1 100100 202 3,5-dichioro-pyridine Ca. 9 1 1 100 100 202Bis(4-pyridyl)glycol- Ca. 8. 6 1 1 100 100 202 Nicotine (i. 1 1 100 211Isonicotimc acid. Ca. 10 1 1 100 100 202 n-Butylnicotinate Ca. 8. 7 1 l100 100 202 Nicotinamide 8 64 1 1 100 10 211 Isonicotinic thionamide.Ca. 9 1 1 100 100 202 B-Picoline 7. 96 1 1' 100 100 202 'y-Picolin 7. 961 1 100 100 202 Imidazole 4. 37 10 1 100 100 112 Inhibitory dose toindicated organism (p.p.m.)

Complex of triphenylborane with the io1lowing Fun. Boo. Boo. Bee.

-Ethylpyridine X X 10 100 3- (4-pyridy1)-propanol-i 100 X 100 1003,5-dichloropyridinc 100 100 100 100 Bis(4-pyridyl)glycol- 100 100 100100 Isonicotim'c acid 100 100 100 100 n-Butylnicotinate. 100 100. 100.100 Isonicotinic thionamide 100 100 100 100 fl-Picoline 100 X 100 100yPicnlinn 100 100 100 100 Imirinvnlc 100 100 100 100 Four of thecomplexes from the preceding tables were further evaluated asthallophyticides as shown below:

Complex of tri- Inhibitory dose to indicated organism (p.p.m.)

. phenylborane with the iollowing Fun. Fun. Bac. Bac. Bac. Boo. Boo.Bee.

Pyridine 10 1 1 10 10 3-bromopyridine 100 100 10 10 X 100 10 Nicotine100 100 10 10 10 X 100 100 Nicotinamide 100 100 10 10 X 100 10Inhibitory dose to indciated organism (p.p.m.) Complex oftriphenylborane with the following- Bac. Baa. Bac. Bac. Bac.

Pyridine 1 3-bromopyridine. 100 100 100 X Nicotine 100 100 10 100Nicotinamide 100 100 10 100 Example 8 Determination of the inhibitorydose of representative complexes of trinaphthyl borane against variousorganisms yielded the following results:

Inhibitory dose to indicated organism Complex of trinaphthylborane withthe following- ThallopKb Aig. Alg. Fun. Bac. phyti- 1 2 3 4 cidal indexAmmonia 4. 74 10 10 X 10 30 Diethylamine- 2. 89 10 10 X 20Trimethylaminm- 4. 13 10 10 X 20 Pyridine-.. 8. 64 10 10 X 10 30 Benzene10 10 X 100 21 Inhibitory dose to indicated organism (p.p.m.) Complex oftrinaphthyl borane with the following- Fun. Bac. Bac. Baa. Baa. 5 7 8 1416 Ammonia 10 100 100 100 10 Diethylamme.- 10 10 10 Trimcthylamme. 10 1010 Pyridine X 100 10 10 X Benzene X 100 Probably a solvate.

Example 9 The inhibiting concentration of representative complexes ofsubstituted triphenylboranes against various rganisms was determined,with the following results:

Inhibitory dose to indicated organism (p.p.m.)

Complex Alg. Alg. Fun. Bac. ThailopKb 1 2 3 4 phyticidal indexTri-p-fluorophenyl-borane:

ammonia 4. 74 1 1 201 Tri-pmethoxyphenylborane: ammonia 4.74 1 1 200Tri-p-flnorophenyl borane:

pyridine 8.64 1 1 201 Tri (p-tolyi) borane ammonia 4.74 1 1 200 phaticamines are applied to various representative organisms in vitro with thefollowing results:

Inhibitory dose to indicated organisms (p.p.m.) Complex oftriphenylflfifif j g ff lu Alg. Fun. Bae. Thallog pKb 1 2 3 4 phyticidalindex Methylarnine 3.19 1 1 100 10 211 Dodeeylamine 3. 7 1 1 10 10 220n-Tetradee l amine 3.8 1 1 10 100 211 Ethylenediamine 4 07 1 1 100 100202 Hexamethylene diamine Ca. 4 10 1 100 111 Tetrahydroiuriurylaminoethanol Cu. 5 1 1 100 100 202 Acetvlaeetone imide Ca. 5 1 1 100 100202 Benzylamine 4. 62 1 1 100 100 202 Inhibitorydose to indicatedComplex of tripbenyllborane with orgamsm the following- Fun. 5 Bae. 11Bae. 12 Bee. 16

Methylamino 100 Dodecylamine 100 100 10 n-Tetrrideeyl amine. 100 X 100100 Ethylenediamine- T 100 100 100 100 Hexamethylzne diamine 100 100Tetrahydrof iriuryl aminoethanoL 100 100 10 100 Aoetylacetone imide- 100100 100 100 Benzylamine 100 100 100 100 Two of the complexes from thepreceding tables are further evaluated as thallophyticides as shownbelow.

Fun. Baa. Baa. Baa. Bac. Bae. Bac. Bae. Bae. 6 7 8 9 10 13 14 15 17Methylarnine-.. Dodecylamine" Example 3 Aqueous solutions containingcomplexes of triphenylborane with a number of secondary aliphatic amineswere applied to various representative organisms with the followingresults:

Inhibitory dose to indicated organisms (p.p.m.)

Complex of triphenylborane with the Alg. Alg. Fun. Bae.ThalloiollowingpKb 1 2 3 4 ph tioidal index Triethylenetetramine, Ca. 31 1 100 10 211 N-alkyl propylene diamine 1 Ca. 3 1 1 100 10 211 n-dodecyl propylene diamine Ca. 3 1 1 100 100 202 N-alkyl propylene diamine 3Ca'. 3 1 1 100 100 202 Dimethylamine. 3. 31 1 1 100 10 211Di-n-propylamine 3. 0 1 1 100 10 211 N'rnethylethanol amine Ca. 5 1 1100 100 202 Plperidine 2. 79 1 1 10 10 220 Piperazine. 4. 19 1 1 100 100202 Morpholine Ca. 5 1 1 100 100, 202

, 1 Available from the Armour Company under the trade designationDuomeen S." This diamine has an iodine value of 515, a melting range of2024 C. and a diamine content of not less than 80%. s V

1 Available from the Armour Company under the trade designation Duomeen12.

3 Available from the Armour Company under the trade designation "DuomeenClf This diamine has an iodine value of about 50, a melting range of3848 C. and a diamine content of not less than 80%.

Inhibitory dose to indicated organism (p.p.m.) Complex oftriphenylborane with the following- Fun. 13:10. Bae Bac.

Triethylenetetramine. 100 10 10 Duom een S 100 100 10 100 N-dodeeylpropylene (ha 100 100 100 100 Dnomeen C 100 100 100 100 Dimethylamine100 Di-n-propvlamin t. 100 100 10 10 NMcthyl ethanolai 100 100 100 100Piperidine c 2 Piperazinm r 100 100 10 100 Morpholine 100 100 100 8 Fourof the complexes from the preceding table are Example 4 Complexes oftriphenylborane aliphatic amines were used to inhibit growth of variouswith several tertiary representative organisms with the followingresults:

Inhibitory dose to indioated organism (p.p.m.1) Complex of triphenyltborane with the following- Alg. Alg. Fun. Bac. ThallopK 1 2 3 4phytloida index Trlmethylamine 4.13 1 1 100 10 211 Tri-n-propvlamine3.26 1 1 100 10 211 3-Dimethylarninopropylamine 08.4 1 1 100 100 202 1Inhibitory dose to indicated Complex of triphenylorganism (p.p.m.)

borane with the following- Fun. Fun. Bae. Bac. Bac. Bae. Bee. 5 6 8 l112 14 16 'Iriniethylaniine 100 100 100 100 Tri-n-propvlamine -1 100 100100 100 3-Dimethylaminopropylamine 100 100 100 100 Example 5 Theinhibitory dose of each of a number of complexes of triphenylborane withrepresentative phosphines was determined against various organisms withthe following inhibitory dose to indicated organism (p.p.m.)

Complex of trlphenylborane with the following- Fun. Fun. Bac. Bac. Bae.Bee. 5 6 7 8 11 12 Tributylphospnine 100 100 100 10 100 100Phenyl-diethylphosphine 100 X 100 X Phenyl-dipropylphosphine X X 100 XExample 12 Inhibitor dose to indicated organism( .m.) i v y pp Samplesof triphenylborane ammonia, tr phenylborane Complex Fm Fm Baa Baa Bm BaaBaa Baa Baa. pyridine, triphenylborane methylamine, trip'henylbor'a'fie6 7 8 11 12 13 14 5 dimethylamine and triphenylborane trimethylaminewere tested to determine their anti-fungal activity by the followgg flggqggfgggg 100 100 10 X 10 1O 10 10 ing technique: Poured agar platesare seeded with the pyspores of the test fungus. A small amount of thecom- X 100 100 X X 10 100 pound to be tested is placed in the center ofthe plates, Tri-p-fiuorophenyli e u h v t f borane:pyridine. 100 H10 10100 100 10 10 after wh ch they mclibat d Hm h 'lri (p-tolyl) borane: thefungus occurs. The width of zones of nhibition surammoma 100 10 X Xrounding the test samples are recorded. The results of Example 10 thetests are shown in the following table. Inhibiting concentrations of anumber of complexes 15 of triphenylborane with weakly basic materialssome of which are Lewis bases having pK values greater than about 10were determined with the following results: Width bfzne MinhibitiohInhibitory dosing-gamed organism 7 TH- Tm Mixture of triphenyl- 'lrTllphenyl phenyl phenyl boranc with the followph nyl ph nyl butane V b0ran e borane 8- Alg. Alg. Fun. Bac. Thalloborano borane monodimethyl- VtripK 2 3 4 phyticiammonia pyridine methyl amine methyldal index amineamine Control-no added basic Alternarjia' 80mm". 10 1 5 i4 23 material10 10 X X 20 Aepergillus nigerfl 4 2 4 7 16 10 10 X X 20 Phizopusnigricans'. 6 1 6 11 1 3 10 10 X- X 20 Stemphg Zium sp--. 5 7 10 10 v 20A 10 10 100 100 22 Glqmerella A I 2,5-dimethyl- 10 10 X X 20 c mgulata4' 1 3 13 20 2,4-dimethyl- 10 10 10 100 31 Trzchophyton5-hydr0xyisoquinoline 10 10 100 100 22 me op ms 9 3 0 8 20 Aniline 10 10100 100 22 .Mzcrospomm Octadecy1amine 10 10 10 10 gypseum 2 6 a 11 19 151,1 dihydro perfluo 0- Mzcrospprgrm hcxylarnine 10 100 X X I 11 amrloumt6 5 10 20 22 t i -ll 8 28 5% 15% it 4-112 C W Dy we 1 L 35 1 Tineacruris; regarded as synononious with T. gypseum and T. m-- ter 'gitavExample 11 2 Scalp Ringworm causative organism.

A number of triphenylborane complexes were evaluated to determine theirutility for inhibition of spore germination of Monolinia' fructicola (anascomycete related to the various rust organisms which undergoes asexual stage of reproduction and which causes brown rot of peaches andother stone fruits) and Alternaria oleracea (a typical imperfect fungus,ie one in 'which a sexual reproduction has not been demonstrated, whichusually causes slight damage to foliage) by the following method, whichis substantially that adopted by the American Phytopathological Societyand described in Phytopathol'o'gy, vol; 33, pp. 627-632 (i943) Spores ofthe two fungi are produced by culturing on potato-dextrose agar slants,removed in distilled water, washed by centrifugation and suspended insucrose-citrate solution at a concentration of 258,000 spores'permilliliter. A small amount of this suspension is added to 2 ml. portionsof the compound to be testediat concentrations of 1, it), 100' and 10%parts per million and. mixed thoroughly. Two drops of each suchsuspension areplaced on a glass slide and held at 72 C. for 20vhoursunder 100 percent relative humidity and germination of spores isobserved. The following table shows the minimum concentration at whichthere is no germination of spores. This test demonstrates the stronglyfungistatic activity of the compounds.

Inhibiting concentration, p.p.m. Complexes of triphenylborane with thefollowing- 7 Mom'li'nia Alternaria fructicola olemcea Ammonia 1 1Decylamme 0. 1 0. 1 Dodecylamine 0. 1 10 Duomeen 12.- 1 1O Duomeen (L.0.1 1 Piporidine... 1 1 Aniline J 1. 1.

Example 13 Incubation Tri- Tri- Triperiod phenyl phenylphenyl- Organismbefore borane borane borane reading ammonia limethylpyridine (days)amine Fusarium oryspcmm 6 3 3 0 Microspomm gypseum 6 3 4 1 2Trichophyton mentagraphytea. 6 4 3 3 Epidermophyton floccosum 10 3 4 2The somewhat greater effectiveness exhibited by the complexes with lowermolecular weight nitrogenous bases is probably due to greater solubilityand ditfusibility under the test conditions. A similar difference inefiect is observed when the complexes with ammonia and pyridine arecompared for toxicity and for corneal and skin irrita tion. The complexwith ammonia shows greater oral toxicityin rats. When applied as 10percent (w./v.)

suspension in corn oil, it also shows more severe corneal irritation inrabbits but is not irritating to the sheared skin of rabbits at thisconcentration.

Example 14 Fifty ml. quantities of potato dextrose agar (prepared indistilled water) are measured into 125 ml. Erlenmeyer flasks andautoclaved at 15 p.s.i. for 15 minutes. The amount of complex requiredto achieve the desired test concentration is added to the sterile mediumwhile it is still liquid. The complexes are formulated as wettablepowder concentrates and the required test dosages are prepared bydilution of the concentrates with water. The inert portion of theconcentrates consists of 92% of a hydrated silica pigment of extremelysmall particle size (available under the trade designation Hi-Sil 101from the Columbia Southern Chemical Corp., Pittsburgh, Pennsylvania), 4%of a nonionic surfactant which is a reaction product of ethylene oxideand polypropylene glycol (available under the trade designation PluronicL-61 from the Wyandotte Chemicals Corporation) and 4% of alignosulfonate dispersing agent (available under the trade designationMarasperse N from the Marathon Corporation, a division of the AmericanCan Company).

Approximately 25 ml. portions of the complex-containing media are thenpoured into sterile plastic Petri plates. After they have solidified,the plates are seeded with the following organisms.

Bacillus subtilis-a saprophytic, gram positive, spore forming bacterium.

Xanthomonas phaseoli-a plantpathogenic, gram negative, non-spore formingbacterium.

Helminthosporium sativum--a plant pathogenic fungus.

Yeast--a mixture of Torula and Saccharomyces species.

The data recorded in the following table indicates whether any growth isobserved at the end of 72 hours of incubation at 72-74 F. denotes nogrowth, denotes growth).

The inhibition of the fungi Graphium ulmi and Fusarium oxysporum byseveral of the complexes of the invention, is demonstrated as follows.(The inhibition of each of these fungi is of practical importance,particularly in the case of Graphium ulmi, the fungus which causes Dutchelm disease.) The following procedure is utilized: Portions of a potatodextrose agar are poured into culture tubes each of which contains aconstriction near its open end which forms a dam for liquid in the testtube when it is laid on its side. Appropriate amounts of the complexesto be tested are mixed into the liquid agar in the tubes; the tubes arelaid on their sides, and the agar is allowed to solidify. Each tube isthen inoculated at a point just behind the dam with a test fungus and isallowed to incubate for several days at approxi- 16 mately 22 C. At theend of the incubation period, the distance (in millimeters) that thefungus has spread across the surface of the treated agar toward theclosed end of the test tube is recorded as a measure of theeffectiveness of the treatment. The results are as follows:

Linear growth (in millimeters) of Graphium ulmi across agar containingvarious concentrations of the complexes over a Linear growth in(millimeters) of Graphium ulmi across agar containing variousconcentrations of the complexes over a four-day incubation periodComplexes of triphenylborane with the following- 50 25 5 p.p.m. ppm.p.p.m. ppm

0 0 18.0 10. 7 0 2 18.3 18.7 0 0 l9. 7 22. U l) 0 l8. 3 21. 0 0 Trace18.3 20. 7 0 3. 5 20. 3 21. 0 0 0 19. 0 21. 3 Control 23. 2

Linear growth (in millimeters) of Fusarium ozysporum across Theseresults demonstrate that the complexes used have a very high degree offungitoxicity with respect to both of the fungi tested.

The triphenylborane complexes are further evaluated in vivo against anumber of representative phytopathogenic fungi in Examples 16 through 20by the standard test methods indicated below, with the results shown.Unless otherwise described, suspensions of the compounds evaluated inthis series of examples are prepared by dissolving 400 mgm. of eachcompound in 5 ml. of acetone, adding 6 ml. of 0.5 percent of asurfactant (Triton X-155, alkyl aryl polyether alcohol) and dilutingwith distilled Water to make 200 ml. of solution, containing 2000 partsper million of the compounds. Lower concentrations are obtained bysuitable further dilutions.

Example 16 The control of early blight of tomatoes by representativetriarylborane complexes is demonstrated as follows. Tomato plants of thevariety Bonny Best are grown in 4 inch pots until about 8 inches tall.They are drenched with a suspension of the chemical used according tothe method of McCallan and Wellman as further modified by McCallan anddescribed in Contributions of the Boyce Thompson Institute, vol. 13, No.3, pp. 93-134 (1943), and vol. 14, No. 2, pp. 71-75 (1948).

The plant is placed on a turntable and rotated slowly while thesuspension employed is applied through a paint spray gun adjusted tospray 220 ml. per minute at 40 p.s.i. air pressure. Each plant issprayed for as long as required to wet the leaf surfaces withoutrun-off. The plant is then permitted to dry and it is sprayed at 20p.s.i. air pressure during 20 seconds with 10 ml. of a suspension of75,000 spores of Alternaria solani per ml. A number of untreated plantsare provided, for control purposes.

The spore suspension is prepared by irradiating a -day old culture ofthe organism on potato-dextrose agar in a Petri dish with ultravioletlight and harvesting the spores 48 hours later. They are brushed intodistilled water with a rubber policeman, filtered through cheese clothto remove mycelium and coarse particles of culture medium, washed bycentrifugation and diluted to the desired concentration.

After application of the spores, the plant is held at 98 to 100 percentrelative humidity at 70 F. for 24 hours and three days later, the smalllesions caused by infection from viable spores are counted. Thepercentage of effectiveness of the various treatments are measured bycomparison with similarly infected control plants. The results ofvarious treatments, at three levels of concentration, are reported inthe following table.

Concentration applied, p.p.m.

Example 17 Control of bean rust by a number of triaryl borane complexesis demonstrated by a procedure similar to that set forth in Example 16.Infected plants are prepared as follows. Beans (Phaseolus vulgaris var.Pinto) are grown in 4 inch pots until the cotyledons are fully expanded.They are thinned to 4 plants per pot and sprayed for 30 seconds at 40p.s.i. air pressure with a 0.5 percent suspension of the spores ofUromyces phaseoli harvested from infested plants. The plants are grownat 60 F. for 24 hours, at 98 to 100 percent relative humidity, toestablish infection. After 3 days, the selected compound is applied byspraying as a suspension (prepared as described above), a number of potsbeing left untreated to serve as controls. About 7 days later the numberof lesions are counted and compared with the controls to determine thepercent of eifectiveness. The results, in terms of percent effectivenessof vairous treatments at the indicated concentrations, are reported inthe following table.

Example 18 Representative complexes were evaluated for control of lateblight of tomatoes by a procedure similar to that of Example 16.Sporangia of Phytophthora infestans are cultured on sterile wheat at 22C., harvested and incubated for 2 hours in tap water at 5 C., so thatswarm spores emerge. This suspension is then applied to tomato plantspreviously sprayed with the selected complex and dried as in Example 16.

The tomato plants are held for 24 hours at 60 F. and 98 to 100 percentrelative humidity and then grown for 7 days. Because there is a tendencyfor fusion of lesions, control is rated by a numerical system as folows:

0no infection 1slight infection 2moderate infection 3severe infectionControl rating of Phytophthora in Complexes of trinhenylborane festansat specified concentrations with the following p.p.m. 16 p.p.m. 3.2p.p.m.

Ammonia 1 1-2 2 3 3 1 2 3 Pyridine 23 23 3 A second series of compoundswere evaluated using the same procedure. The results are reported in thefollowing table, and the effectiveness is rated as percent control ofthe fungus.

The effectiveness of certain of the complexes in controlling organismscausing decay of seeds is shown as follows: Soil heavily infected withseed-decaying or damping-off organisms, mainly Pythium ultimum, ispotted in threeinch pots. Fifty ml. drench treatments of the respectivecomplexes are applied at total dosages of 50, 25, and 12.5 milligramsper pot. Ten seeds of Pisium sativum var. susceptible Perfection peasare planted in each pot 48 hours after the drench treatment and theeffectiveness of the complexes in controlling the seed-decayingorganisms is measured as the percent appearance or emergence ofseedlings from the seeds. The results of treatment with variouscomplexes expressed in terms of percent emergence of the seedlings aregiven in the following table at the three dosages indicated.

Percent emergence of pea seedlings Complex of tripheuylborane atindicated dosages (mg/pot) with the following Decylamine 80 60 80Dodecylamine. 100 80 Tetradecylamin 60 Octadecylamine 80 40 40N-dodecylpropylene diarni 100 100 60 Ng SCHmNHR (Duome 6o Phenfciffifilfi'ehs'fiiiifi'" 20 Control (no treatment) 0 0 0 In a similarprocedure (except that four-inch pots are a used), ten of the pea seedsare planted in the infected soil which is then watered with 100 ml. ofan aqueous solution,-containing 100 mgm. of the complex oftriphenylborane with ammonia. The pots are placed on benches andemergence after 10 days is determined as well as subsequent growth ordamping-off. It is found that there is some retardation of germination,but there is about 60 to 90 percent emergence with about 50 to 60percent stand of plants not stunted or subsequently damped-01f, evenwhen planting of seeds is delayed for 6 days after treatment of thesoil.

In another series in which various complexes according to the inventionare evaluated, the following procedure is used: The complexes areprepared for testing as 25% dust concentrates in a finely divided inertdiluent, such as diatomaceous earth or a clay. The chemicals are applieddirectly to susceptible peas of the variety Laxtons Progress by tumblingthem with weighed amounts of seed until the seed is uniformly and evenlycoated with the desired amount of chemical. Two sheets of paper towelare next wetted by immersion in water and heavily infested Pythium soilthen spread over the towels to a depth of about A of an inch. Fiftytreated seeds are uniformly distributed over the soil, a third wet towelplaced on top and the whole is rolled up to form a so-called doll. Threedolls constituting three replicates are prepared per treatment. Thedolls are then placed in aluminum containers and held at 45 to 50 F. forfour days after which they are removed to room temperature and held foran additional three to four days to permit germination of the seed.Three dolls of untreated seeds in infested soil constitute the control.Untreated seeds in dolls of vermiculite give an index of thegerminability of the seed lot being used and establishes the amount ofgrowth possible under the conditions used, as a check. In addition,several lots utilizing 2,3-dichloro-1,4-naphthoquinone (a commerciallyavailable chemical which is useful in controlling pre-emergencedamping-off of peas) are added for comparison.

At termination of the procedure, the dolls are opened and the seedexamined for: (1) Number germinated with roots over A inch in length.(2) Seeds firm and free from rot.

(3) Seeds rotted and decomposed. (4) Root damage or other abnormalgrowth characteristics. The results obtained are summarized in thefollowing table:

Treatment: Complex of triphenyl- Dosage Percent Percent borane with thefollowing-- oz./bu. germinadisease tion control Piperidine 1 4 58 82 255 80 1 56 79 71 80 $4 48 64 Ammonia 4 65 96 2 74 92 1 71 83 83 88 $47.3 82 Trimethyl amine 4 89 100 2 73 96 l 87 93 M 79 88 $4 54 80 Sodiumhydroxide 4 36 64 2 48 72 1 42 70 2,3-diehloro-1,4naphthoquinone g :2; 117 13 8 3 $4 0 Control 0 8 0 Check (vermiculite) 0 93 1 Some injury tothe seeds noted.

Example 20 The complex of triphenylborane with ammonia was employed inthe procedure described in Example 19 in which untreated seeds areplanted in infected, previously drench-treated soil. In this case,four-inch pots are utilized and filled with soil heavily infected withRlzizoctonia solani, and drenched with 100 ml. of an aqueous solutioncontaining 100 mg. of the complex. Cotton seedlings are then planted inthe pots and emergence is determined as before. There is about percentemergence of seedlings (the initial growth of which is somewhatretarded), but there is no damping off of the seedlings caused by thismold.

Example 21 The compounds were evaluated from control of the fungiHelminthosporium sativum and Allernaria sp. contained within and on thesurface of naturally infected barley seed as follows: Heavily infectedseed is immersed for 15 minutes in aqueous solutions of the variouscomplexes at the indicated concentrations. The complexes are formulatedas 50% wettable powder concentrates and the required dosages areprepared by dilution of the concentrates with water. The inert portionof the concentrates consists of 92% of Hi-Sil 101 bulk extender, 4% ofPluronic L-61 wetting agent and 4% of Marasperse N dispersing agent.After 15 minutes immersion, the solution is drained off and the seed isplated out on petri dishes containing moistened filter paper. Lack ofcontrol is indicated by the dark colored organism sporulating inprofusion on the seed surface and on the filter paper adjoining theseed. Data recording percent germination and percent uninfected seedsare taken seven days after initiation of the test, the percentgermination indicating the relative safety or phytotoxicity of thechemical.

Concen- Percent Percent Complex tration, germinauninfected ppm. tionseeds Triphenylhorane: ammonia 10. 000 26 1,000 66 100 100 84 92Tnphenylborane: piperidine 10.000 84 100 1, 000 92 7s r00 92 52Tr1phenylborane: trimethylamine 10, 000 0 100 1, 000 82 100 100 100 9810 98 66 Triphenylborane: pyridine 10, 000 74 100 1, 000 72 80 100 7s 56Trrphenylborane: SOdllllTl hydroxido. 10. 000 0 100 1, 000 32 100 100 40on Tnnaphthylhorane: ammonia 10, 000 98 84 1, 000 94 7O 100 94 36Trinaphthylboraue: pyridine 10,000 86 58 1, 000 92 62 100 86 4sTrmaphthylborane: benzene 10. 000 88 94 1,000 82 72 100 96 38 Untreatedcontrol 88-90 30-40 Example 22 The utility of the complexes of theinvention for control of root-rot in peas is shown by the results of thefollowing procedure: Levels of treatment of 20, 40, and 80 mg. perS-inch pot (i.e. 3 pounds of soil) are utilized in four replicates. Eachpot is steam sterilized and then 21 inoculated and tested according tothe following schedule:

Elapsed time from Operation 1 sterilization y Pea seedlings infestedwith Aphanomyces eutrziches (the causal fungus of pea root-rot) planted.

All plants observed to be dead or dying; tops removed.

55 Soil in pots drenched with aqueous suspension of the zoospores of thefungus.

62 Second zoospores suspension applied; chemicals mixed into soil.

63 Six pea seeds planted in each pot.

69... Third zoospores suspension applied.

102 Final notes made on root-rot reading and plant height.

1 A high level of moisture was maintained throughout the entire period.2 A total of about 3,400,000 zoospores were added to each pot in thethree applications.

The effects of the chemical treatments upon plant height and root rotlevel of the peas were found to be as follows:

Total plants Appear- Plant Root- Treatment Rate, ance, ht., rot inmg/potEmerged, Scored, score 2 inches dex 72 102 3/16 days 1 days 1 Sterilecontrol 20 22 0.8 12. 8 2.0 Inoculated control- 22 24 5. 2 6. 2 9. 5 2223 4. 0 5. 1 7. 8 21 22 4. 2 5. 9 6. 6 Triphenylbolane:

pyridine 20 21 22 2. 2 9. 1 5. 1 40 22 23 1. 2 10. 2 4. 2 80 23 23 1. 59. 7 5. 9 Triphenylborane:

trimethylamine..- 20 22 22 3. 0 8. 4 6. 8 40 23 23 1. 8 10. 4 3.6 80 2224 1.0 8. 4 1. 9

1 Elapsed time from sterilization.

Z Scored for above-the-ground symptoms: 0=no symptoms; 6=all plantsdead.

3 Root-rot index: 1=no symptoms; =all plants dead.

Example 23 The inhibition of growth of microorganisms in water which isrecirculated through evaporative cooling towers is a useful applicationof the compounds herein described. Fungi tend to destroy the woodenbaiiles to such cooling towers While algae, protozoa and bacteria allcause slime. To show the utility of various triarylboranes for thispurpose, a series of nine experimental cooling tower models were set up.Each model contained 300ml. of fresh lake water in a wide mouth jar. Apiece of white pine wood, 2 inches by 2 inches by inch thick wassuspended above the surface at an angle such that one edge was barelytouching the surface of the water, and the opposite edge was 1 inchabove the surface of the water. A glass tube A inches in diameter wasinserted through the wood 1 /2 inches from the edge which touches thewater and 1 inch from the adjacent edge. The opening of the glass tubewas flush with the surface of wood. A slow current of water wascirculated from the jar over the piece of wood and thus back into thejar by an air lift pump connected to the glass tube.

All of the jars were placed on a shelf under strong illumination from afluorescent daylight lamp in order to promote algal growth. Thetemperature was maintained at 22i3 C. After 17 days with circulation ofwater as described, the contents of each vessel was examined. The waterwas found to be turbid owing to the growth of various microorganisms.One vessel was then continued untreated as a control and the others weretreated with thallophyticidal compositions of the invention by additionof amounts of triarylborane complexes at levels of 1 part per million orat 10 parts per million. Circulation of 22 water was continued and thevessels were examined as before after 24 hours and again after intervalsof one week, two weeks and three weeks. Each of the vessels containingonly 1 part per million of triarylborane amine complex was treated withan additional 1 part per million of the same complex at the end of thefirst week. It was found that at l or 2 parts of the complex per millionthere is some effect as compared to the control on the accumulation ofmicroorganisms which are evident as turbidity in the water and a greensediment on the botom of the vessel with any of the five complexesemployed, namely triphenylborane ammonia, triphenylborane pyridine,tri-p-tolylborane ammonia, tri-(p-fiuorophenyl)- borane ammonia andtri-(p-fluorophenyl)borane pyridine. In the three vessels in whichtriphenylborane ammonia, tri-p-tolylborane ammonia andtri-(p-fluorophenyl)borane ammonia, respectively, were present at 10ppm. there was a clearly evident effect. The water was visibly lessturbid than in the control vessel and the residue on the bottom was lessin amount and tends to be abnormally pale and blanched in color clearlydemonstrating the thallophyticidal action of these complexes.

Example 24 It is found that in water flooding of oil fields for thesecondary recovery of oil, the use of an agent to kill sulfate-reducingbacteria results in reduced corrosion of pipes and lessens problems ofcleaning well holes. The effect of the bacteria is to produce hydrogensulfide from sulfates and thereby enhance corrosion of iron andadditionally precipitate finely divided ferrous sulfide which tends toplug the porous passageways in the oil producing formation. The utilityand effectiveness of the process of the present invention as applied tosulfate-reducing bacteria is illustrated as follows: I

An enrichment culture of sulfate-reducing bacteria is isolated in alactate-salts medium incubated under anaerobic conditions. This cultureis used to inoculate tubes of the following medium supplemented with0.1% yeast extract (percentages given by weight).

Percent Potassium monohydrogen phosphate 0.7 Potassium dihydrogenphosphate 0.3 Magnesium sulfate heptahydrate 0.01 Ammonium sulfate 0.1Sodium lactate 0.5 Calcium carbonate 0.2 Reduced iron powder 0.2 Sodiumchloride 1.0 Water, q.s. to make 100.0%.

One ml. of inoculum was placed in each 27 ml. tube of medium. andvarying amounts of the triphenylborane complexes of ammonia, pyridine,methylamine, dimethylamine and trimethyl amine were added to the testtubes. Each of these five complexes was found to give completeinhibition of the sulfate-reducing bacteria for the duration of theexperiment (10 days) and at the lowest concentration employed (2 ppm.for the dimethylamine complex and 1 ppm. for the others). The controlswere found to grow black with FeS in three days, indicating that thebacteria therein were active.

In a second comparative evaluation, a liquid medium is prepared indistilled water to contain (by weight):

The organism used was a species of sulfate-reducing Desulfovibrioisolated from brackish oil-well-fiooding water which grows anaerobicallyin this medium so readily that the medium becomes black in one daybecause of precipitation of ferrous sulfide. In duplicate runs,triphenylborane ammonia was included in the medium at concentrations of0.1 and 0.5 part per million. Similarly, a commercially availablegermicide used for treatment of oil flooding water was used incomparative runs at l and 5 parts per million. The media containingtriphenylborane ammonia at 0.5 p.p.m. and the commercial germicide at 5p.p.m. show complete inhibition for 32 days, that is, there is noprecipitation of ferrous sulfide, and that containing triphenylboraneammonia at 0.1 p.p.m. shows complete inhibition for 20 days whereas thecommercial germicide at 1 p.p.m. shows no inhibition whatever.

'Triphenylborane ammonia is thus found to be at least about 10 times aseffective as the commercial germicide for inhibiting sulfate-reducingbacteria. Similar results are obtained when other triarylboranecomplexes are employed.

In a third comparative evaluation, the effect of the complex oftriphenylborane with ammonia upon the growth of the sulfate-reducingbacteria in water containing varying salt concentrations was measured.The bacteria, medium and technique used were the same as that set forthimmediately above. The results are set forth in the following table, inwhich indicates that growth of the bacteria occurred and indicatesinhibition of the bacteria.

Concentration Baeter'al growth or of tripheninhibition Concentration ofsodium chloride, ylboranepercent ammonia,

p.p.m. After 3 After 28 days days 1 0 0. 1 0. 1, 0 5.0 2 0 0 0.1 0. 51.0 a. o 4 0 0 0.1 0. 5 1.0 5. 0 8 0 0 o. 1 0. 5 1.0 5.0

Example 25 In this example, the stability of the triarylborane complexesin soil burial applications and their activity against certain bacteria,yeasts and fungi of the types found in soils are evaluated.

The complexes are formulated as 50% wettable powder concentrates and therequired dosages are prepared by dilution of the concentrates withwater. The inert portion of the concentrates consists of 92% of Hi-Sil101 'bulk extender, 4% of Pluronic L-61 wetting agent and Growth index:

0--No growth 1-Slight trace of growth 2-Slight growth 3-Moderate growth4Heavy growth 5-Very heavy growth The results of several suchevaluations run on the triarylboranes are as follows:

Growth index after indicated Concentest period Complexes ottration,

p.p.m.

2 3 4 5 6 days days days days days Triphenylborane-ammonia 9, 000 0 0 0900 0 1 2 2 5 5 Triphenylborane-trimeth- 9, 000 0 0 0 0 ylamine. 900 0 00 90 1 1 1-2 Triphenylbor one-pyridine. 9, 000 0 0 900 0 2 90 2 5Triphenylborane-sodium 9, 000 0 0 hydroxide. 900 0 0 90 2 2Trinaphthylborane ben- 9, 000 0 0 0 zene. 900 0 1 1 90 1 3 4 Control,untreated 0 35 5 5 1 Solvate.

Example 26 In this example, several of the triarylborane complexes aretested as biocides for the protection of wood in soil burial tests.One-inch cubes of white pine are submerged in 0.1% solutions (in ketonesolvents) of the chemicals being evaluated, the solutions beingcontained in beakers. The beakers are placed in vacuum desiccators whichare evacuated to below the solvent vapor pressure for approximately onehour, brought to atmospheric pressure and left overnight, the woodentest pieces remaining submerged in the solutions during this time. Theblocks are then removed, air dried and placed in jars over rich, moistgarden soil and heavily inoculated with a water suspension of thewood-destroying fungus Pullularia pullulans. The jars are incubated atroom temperature, water being added periodically to maintain highlyhumid conditions. After periods of 50 days and 64 days of incubation,the blocks are checked for fungus and rated from 0 for no fungus growthto 5 for extreme fungus growth. The results are as follows:

In another test, one-inch cubes of white pine are soaked for 1-2 hoursin solutions of varying concentration of the 25 complex oftriphenylborane-ammonia in acetone and incubated and evaluated as above.The results are:

Fungus Fungus growth growth Concentration of Triphenylboranc in acetonerating rating Solution after after 50 days 64 days incubation incubationWhat is claimed is:

1. A method of inhibiting the growth of microorganisms of the divisionThallophyta which comprises contacting the said microorganisms with athallophyticide selected from the class consisting of:

in an amount effective to inhibit the growth of said microorganisms.

2. A method according to claim 1 wherein said thallophyticide is acomplex of triphenylborane with an alkali metal hydroxide.

3. A method according to claim 1 wherein said thallophyticide is thecomplex of triphenylborane with sodium hydroxide.

4. A method according to claim 1 wherein said microorganisms arebacteria.

5. A method according to claim 1 wherein said microorganisms are algae.

6. A method according to claim 1 wherein said microorganisms are of theclass Phycomycetes.

7. An agronomical process for the combatting of microorganisms of theclass Thallophyta which comprises impregnating the soil with aneffective amount not less than about parts per million of athallophyticide according to claim 1.

8. A method for the prevention and control of root rot in the leguminousplants which consists in treating the soil with a thallophyticideaccording to claim 1 and growing leguminous plants in said treated soil.

9. A method of inhibiting the growth of microorganisms of the divisionThallophyta in cooling tower water which comprises treating said waterwith a thallophyticide according to claim 1.

10. A method according to claim 1 wherein said thallophyticide is acomplex of tri-p-tolylborane with a Lewis base having a pK less thanabout 10.

11. A method according to claim 1 wherein said thallophyticide is acomplex of tri-p-xylylborane with a Lewis base having a pK less thanabout 10.

12. A method according to claim 1 wherein said thallophyticide is acomplex of tri-(p-fluorophenyl) borane with a Lewis base having a pKless than about 10.

13. A method according to claim 1 wherein said thallophyticide is acomplex of tri-(p-methoxyphenyl) borane with a Lewis base having a pKless than about 10.

14. A method according to claim 1 wherein said thallophyticide is acomplex of triphenetylborane with a Lewis base having a pK less thanabout 10.

15. A method according to claim 1 wherein said thallophyticide is acomplex of trinaphthylborane with a Lewis base having a pK less thanabout 10.

16. A method according to claim 1 wherein said thallophyticide is acomplex of triphenylborane with a Lewis base having a pK less than about10.

17. A method according to claim 16 wherein said microorganisms arebacteria.

18. A method according to claim 16 wherein said microoganisms are of theclass Phycomycetes.

19. A method of inhibiting the growth of microorganisms of theclassification Thallophyta, which comprises contacting the saidmicroorganisms with triphenylborane in an amount eflective to inhibitthe growth of said microorganisms.

20. A method of inhibiting the growth of microorganisms of theclassification Thallophyta, which comprises contacting the saidmicroorganisms with trinaphthylborane in an amonut etfective to inhibitthe growth of said microorganisms.

21. A method of inhibiting the growth of microorganisms of the divisionTha'llophyta which comprises contacting the said microorganisms withtri-p-tolyl borane in an amount efiective to inhibit the growth of saidmicroorganisms.

22. A method of inhibiting the growth of microorganisms of the divisionThallophyta which comprises contacting the said microorganisms withtri-p-xylylborane in an amount effective to inhibit the growth of saidmicroorganisms.

23. A method of inhibiting the growth of microorganisms of the divisionThallophyta which comprises contacting the said microorganisms withtri-(p-fluorophenyl) borane in an amount effective to inhibit the growthof said microorganisms.

24. A method of inhibiting the growth of microorganisms of the divisionThallophyta which comprises contacting the said microorganisms withtri-(p-methoxyphenyl) borane in an amount eifective to inhibit thegrowth of said microorganisms.

25. A method of inhibiting the growth of microorganisms of the divisionThallophyta which comprises con tacting the said microorganisms withtriphenetyl borane in an amount effective to inhibit the growth of saidmicroorganisms.

26. A thallophyticidal composition comprising a thallophyticide selectedfrom the class consisting of:

together with a surface active agent as a dispersant therefor.

27. A thallophyticidal composition according to claim 26 wherein saidthallophyticide is a complex of triphenylborane with a Lewis base havinga pK less than about 10.

28. A thallophyticidal composition according to claim 26 wherein saidthallophyticide is a complex of trinaph- 2? thylborane with a Lewis basehaving a pK less than about 10.

29. A thallophyticidal composition according to claim 26 wherein saidthallophyticide is the complex of triphenylborane with sodium hydroxide.

30. A thallophyticidal composition consisting essentially of anefiective amount of from about 0.1 part per 23 million to about 1percent of triphenylborane in a compatible inert diluent together with asurface active agent as a dispersant therefor.

References Cited in the file of this patent Berichte: 57B, page 813(1924); 61B, page 271 (1928); 63B, page 924 (1930); 6413, page 2112(1931).

1. A METHOD OF INHIBITING THE GROWTH OF MICROORGANISMS OF THE DIVISIONTHALLOPHYTA WHICH COMPRISES CONTACTING THE SAID MICROORGANISM WITH ATHALLOPHYTICIDE SELECTED FROM THE CLASS CONSISTING OF: (1)TRIPHENYLBORANE, (2) ALKYL-SUBSTITUTED TRIPHENYLBORANES, (3)HALOGEN-SUBSTITUTED TRIPHENYLBORANES, (4) ALKOXY-SUBSTITUTEDTRIPHENYLBORANES, (5) TRINAPHTHYLBORANE, (6) COMPLEXES OFTRIPHENYLBORANE WITH LEWIS BASES HAVING A PKB LESS THAN ABOUT 10 (7)COMPLEXES OF ALKYL-SUBSTITUTED TRIPHENYLBORANES WITH LEWIS BASES HAVINGA PKB LESS THAN ABOUT 10 (8) COMPLEXES OF HALOGEN-SUBSTITUTEDTRIPHENYLBORANES WITH LEWIS BASES HAVING A PKB LESS THAN ABOUT 10 (9)COMPLEXES OF ALKOXY-SUBSTITUTED TRIPHENYLBORANES WITH LEWIS BASES HAVINGA PKB LESS THAN ABOUT 10 AND (10) COMPLEXES OF TRINAPHTHYLBORANE WITHLEWIS BASES HAVING A PKB LESS THAN ABOUT
 10. IN AN AMOUNT EFFECTIVE TOINHIBIT THE GROWTH OF SAID MICROORGANISMS.